WO2012062066A1 - Alternating current-driven led light emitting device - Google Patents

Abstract

An LED light emitting unit comprises an LED chip (2) and a light-emitting material (1) emitting light excited by the LED chip (2). The usage life of the light-emitting material is 1-100 milliseconds; the LED chip (2) is a single PN node LED chip; the LED light emitting unit is driven by an alternating-current with a frequency not lager than 100 Hz. An alternating current-driven LED light emitting device comprises the LED light emitting unit. The LED light emitting device avoids using an alternating current-driven LED chip integrated by multiple micro crystal grains, thus realizing a modest fluctuation of the brightness in the alternating-current period, simple production, and low cost, and solving the stroboscopic problem caused by the alternating-current power supply and the heat radiating problem caused by micro chip integration.

Description

 AC LED light-emitting device

 The invention relates to an alternating current LED lighting device, and belongs to the technical field of manufacturing an alternating current LED lighting device.

Background technique

 At present, LEDs are used in the fields of illumination, display and backlight, and have attracted extensive attention as the most promising next-generation lighting method due to their advantages of energy saving, durability and pollution-free. Conventional LED chips use DC power as the driving current. However, most of them are provided by household frequency, commercial or commercial power, and most of them are provided by power frequency AC. Therefore, when using LEDs for lighting and other purposes, it is necessary to use a rectifier transformer to convert AC-DC. In order to ensure the normal operation of the LED. However, in the process of AC-DC conversion, there is up to 15~30% of power consumption, and the conversion device not only has a short service life, but also has a high cost, and is also time-consuming and inefficient in installation.

 CN100464111C discloses an alternating current LED lamp which uses LED chips of different illuminating colors in parallel in an alternating current power source, and mainly describes LED chips of different colors to form white light together, and specific circuits thereof, such as red, green and blue light emitting chips, There is no luminescent powder involved.

 International Patent WO 2004/023568A1 "LIGHT-EMITTING DEVICE HAVING LIGHT-EMITTING

In ELEMENTS, it is proposed to mount a plurality of small LED chip arrays on a sapphire substrate to provide an illumination device that can be driven by an AC power source.

 American Specialist lj US 7, 489, 086 B2 "AC LIGHT EITTING DIODE AND AC LED DRIVE METHODS AND APPARATUS" provides an AC LED device, which is a plurality of LEDs operating at frequencies above 100 Hz The integrated LED lighting device of the chip utilizes the visual persistence effect of the human eye to compensate for the strobe of the LED device under AC work.

 Based on similar ideas, Seoul Semiconductor and Taiwan Industrial Technology Institute have integrated a large number of ultra-fine LED dies on a single substrate, which is called an AC LED chip. At the core of the above-mentioned AC LED technology is a large number of micro-die integrated packaged microelectronic circuit processing technologies. For example, the AC LED chip of the Taiwan Industrial Technology Research Institute integrates hundreds of tiny LEDs on a 1 mm square area. However, such an AC LED chip is difficult to process, and a large number of microchips integrated in a small substrate space may cause problems such as poor heat dissipation.

In order to realize the LED lighting device for use in the fields of illumination, display and backlight, etc., to overcome the stroboscopic problem in the case of supplying power in an alternating current mode, those skilled in the art have been working tirelessly. Summary of the invention

 The technical problem to be solved by the present invention is to provide a new AC LED lighting device that solves the stroboscopic problem in the AC power supply mode at low cost.

 The AC LED lighting device of the present invention does not use the existing multi-microchip integrated AC LED chip, but uses an ordinary single PN junction LED chip, and a phosphor with a specific luminescence lifetime, and a phosphor luminescence with a specific luminescence lifetime. It is used to compensate for the stroboscopic phenomenon of LED devices during power frequency AC fluctuations of no more than 100 Hz, which is simple in production and low in cost.

 The technical solution of the present invention comprises: an LED chip and a luminescent material capable of emitting light under excitation of the LED chip, wherein: the LED chip comprises only one luminescent PN junction, and the luminescent lifetime of the luminescent material is 1 to 100 ms (preferred) 10-30ms), through the continued illumination of the luminescent material (afterglow) to compensate for the illuminance of the chip when the chip is powered off under non-constant current conditions.

 According to the definition of luminescence, the luminescence lifetime of the luminescent material is the time required for the luminescence intensity of the material to fall to 1/e of the maximum intensity at the time of excitation.

 With the above luminescent material, the LED lighting unit of the present invention can use an LED chip containing only one light-emitting PN junction without using an integrated packaged AC LED chip.

 The above-mentioned LED lighting unit uses an alternating current having a frequency of not more than 100 Hz, in particular, an alternating current of 50-60 Hz.

 The light emitted by the LED chip used in the above LED lighting unit may be ultraviolet, visible or infrared light.

The luminescent material is a combination of one or more inorganic and/or organic luminescent materials. The luminescent material is a combination of one or more inorganic and/or organic luminescent materials. For example: CaS _: Eu ²⁺ _; CaS:

Bi ²⁺ , Tm ³ ; ZnS: Tb ³⁺ ; CaSrS ₂ : Eu ²⁺ , Dy ³⁺ ; SrGa ₂ S ₄ : Dy ³⁺ ; Ga ₂ 0 ₃ : Eu ³⁺ ; (Y, Gd) B0 ₃ : Eu ³⁺ ;

Zn ₂ Si0 ₄ :Mn ²⁺ _; YB0 ₃ :Tb ³⁺ ; Y(V,P)0 ₄ :Eu ³⁺ ; SrAl ₂ 0 ₄ :Eu ²⁺ ; SrAl ₂ 0 ₄ :Eu ²⁺ ,B ³⁺ ;

SrAl ₂ 0 ₄ :Eu ²⁺ , Dy ³⁺ , B ³⁺ _; BaAl ₂ 0 ₄ :Eu ²⁺ ; CaAI ₂ 0 ₄ :Eu ²⁺ ; Sr ₄ Al ₁₄ 0 ₂₅ :Eu ²⁺ ;

Sr ₄ Al ₁₄ 0 ₂₅ : Eu ²⁺ , Dy ³⁺ , B ³⁺ ; Sr ₃ Si0 ₅ : Eu ²⁺ , Dy ³⁺ ; BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , Mn ²⁺ ;

Tb(acac) ₂ (AA)phen _; Y ₂ 0 ₂ S:Eu ³⁺ ; Y ₂ Si0 ₅ :Tb ³⁺ ; SrGa ₂ S ₄ :Ce ³⁺ ; Y ₃ (Al,Ga) ₅ 0 ₁₂ :Tb ³⁺ ;

Ca ₂ Zn ₄ Ti ₁₅ 0 ₃ 6 :Pr ³⁺ ; CaTi0 ₃ :Pr ³⁺ _; Zn ₂ P ₂ 0 ₇ :Tm ³⁺ ; Ca ₂ P ₂ 0 ₇ :Eu ²⁺ , Y ³⁺ ; Sr ₂ P ₂ 0 ₇ : Eu ²⁺ , Y ³⁺ ;

Lu ₂ 0 ₃ : Tb ³⁺ , Sr ₂ AI ₆ 0ii: Eu ²⁺ ; Mg ₂ Sn 0 _{4 :} Mn ²⁺ ; CaAI ₂ 0 ₄ : Ce ³⁺ , Tb ³⁺ _; Sr4AI ₁₄ 025 : Tb ³⁺ ;

Ca ₁₀ (PO ₄ ) ₆ (F,Cl) ₂ : Sb ³⁺ , Mn ² _; Sr ₂ MgSi ₂ 0 ₇ :Eu ²⁺ _; Sr ₂ CaSi ₂ 0 ₇ :Eu ²⁺ _; Zn ₃ (P04) ₂ : Mn ²⁺ , Ga ³⁺ _;

CaO:Eu ³⁺ _; Y ₂ 0 ₂ S:Mg ²⁺ , Ti ³⁺ _; Y ₂ 0 ₂ S:Sm ³⁺ ; SrMg ₂ (P0 ₄ ) ₂ : Eu ²⁺ , Gd ³⁺ ; BaMg ₂ (P0 ₄ ) ₂ : Eu , Gd'⁺; Zn ₂ Si0 ₄ : Mn ⁺ , As ³⁺ ; KLaF4 : E + ; CdSi0 ₃ : Dy ^J+ _;

One or more of MgSi0 ₃ :Eu ²⁺ , Mn ²⁺ .

 The LED lighting device of the present invention comprises the above LED lighting unit and driving circuit, and the driving circuit may be a single-direction series circuit, an anti-parallel circuit and a bridge rectifier circuit, as shown in FIGS. Or a combination of any of the above circuits. The alternating current drive circuit has a frequency of no more than 100 Hz.

 In addition, the LED lighting device of the present invention further comprises a light guiding cover layer, which is a non-planar light guiding structure. The light-emitting layer of the LED chip and the light-emitting material are reflected, refracted, scattered, and homogenized by the light-guiding cover layer to be finally mixed to lead to uniform surface light. Wherein, the light guiding cover layer is a lens or other transparent covering layer, wherein non-luminescent material particles having a particle diameter of less than 5 micrometers may be doped, so that the light output of the chip is evenly scattered. Advantageous Effects of Invention: The present invention uses a luminescent material having a specific luminescence lifetime, and when the current period changes, the luminescence of the luminescent material is maintained for a certain period of time in the cycle, thereby making up for the fluctuation of the alternating current.

The effect of the strobe of the LED chip keeps the light output of the illuminating device stable during the AC cycle. In addition, since the LED light-emitting device of the present invention can use an LED chip containing only one light-emitting PN junction without using an integrated packaged AC LED chip, the LED chip does not work for half a cycle in the AC cycle, so that the thermal effect thereof is lowered, thus Helps overcome the series of problems caused by the heat generated by the chips in the existing LED lighting devices. Therefore, the LED light-emitting device of the invention has stable and reliable processing and simple cost, and opens up a new way for the LED light-emitting device.

Instruction sheet

 1 is a schematic diagram of a unidirectional series circuit of an alternating current LED lighting device of the present invention.

 2 is a schematic diagram of an anti-parallel circuit of an alternating current LED lighting device of the present invention.

 FIG. 3 is a schematic diagram of a bridge rectifier circuit with a normally conducting LED chip in the AC LED lighting device of the present invention.

 FIG. 4 is a schematic diagram of a bridge rectifier circuit in which an alternating current LED light-emitting device of the present invention is electrically turned on.

 Figure 5 is a schematic diagram of the composition of the LED light-emitting unit, 1 is a light-emitting material, or a light-emitting layer composed of a light-emitting material and a transparent medium; 2 is an LED chip.

The above content of the present invention will be further described in detail below by way of specific embodiments of the embodiments. However, the scope of the above-mentioned subject matter of the present invention should not be construed as being limited to the following examples, and the technology implemented based on the above-described contents of the present invention is within the scope of the present invention. Especially in the basic circuit composition, the embodiment of the present invention only gives the simplest anti-parallel circuit, but the circuit of the AC LED lighting device of the present invention is not limited thereto, and includes, for example, a unidirectional series and a bridge. Circuit. detailed description

 The AC LED lighting device of the present invention does not use the existing multi-microchip integrated AC LED chip, but uses an ordinary single PN junction LED chip, and a phosphor with a specific luminescence lifetime, and a phosphor luminescence with a specific luminescence lifetime. It is used to compensate for the stroboscopic phenomenon of LED devices during power frequency AC fluctuations of not more than 100 Hz, which is simple in production and low in cost.

 Specifically, the LED lighting unit includes an LED chip and a luminescent material capable of emitting light under excitation of the LED chip, wherein: the luminescent material has an illuminating lifetime of 1 to 100 ms (preferably 10 to 30 ms), and the LED chip is An LED chip comprising only one illuminating PN junction, the LED lighting unit being driven by an alternating current having a frequency of no more than 100 Hz.

 The above-mentioned LED lighting unit uses an alternating current having a frequency of not more than 100 Hz, in particular, an alternating current of 50-60 Hz.

 The following Example 1-12 uses the luminescent material of Table 1 and a commercially available single PN junction LED chip, and the resulting LED illuminating device is packaged by a general sealing technique.

 Example 1-12 Table 1

Blue light

9 Sr ₄ Al ₁₄ 0 ₂₅ :Eu ²⁺ , Dy ³⁺ , B 25 ms

 (460 nm)

 Blue light

10 MgSi0 ₃ :Eu ²⁺ , Mn ²⁺ 5ms

 (450 nm)

 Blue light

11 SrAl ₂ 0 ₄ :Eu ²⁺ , B ³⁺ 100 ms

 (460 nm)

 Infrared

12 KLaF ₄ : Er ³⁺ 34 ms

 (980 nm) Test Example 1 Luminance brightness in an alternating current period in the embodiment of the present invention

Table 2 shows the illuminance in 20 milliseconds taken by the Sarnoff CAM512 high-speed scientific camera taken by the AC LED lighting device of the embodiment under the drive of 50 Hz. Reference Example 1 is a yellow luminescent material YAG: Ce (lighting lifetime of 100 ns) on a commercially available 460 nm blue chip package. The alternating current driving LED illuminating device is formed in the same manner as in the embodiment 1-10, and the reference sample 2 is commercially available. The green long-life material SrAl ₂ 0 ₄ :Eu, Dy (luminous lifetime greater than 1 second) on the 460 nm blue chip package drives the alternating current driving LED light emitting device in the same manner as in the embodiment 1_10. The luminance data in Table 2 is relative brightness and is dimensionless.

 Table 2

 Room

 3. 33 6. 66 9. 99 13. 32 16. 65 19. 98 milliseconds milliseconds milliseconds milliseconds milliseconds

Reference 1 2265 3466 0 2153 3570 0 Reference 2 640 866 620 784 846 611 Example 1 3136 3425 1865 3287 3500 2086 Example 2 3160 3230 1620 2980 3123 1483 Example 3 2786 2963 2000 2935 2983 1962 Example 4 2790 2900 1352 2723 2845 1293 Example 5 2877 2969 2091 2776 2914 1932 Example 6 2543 2669 2002 2711 2814 1912 Example Ί 1544 2134 1608 1478 2289 1509 Example 8 1921 2336 1750 1889 2398 1801 Example 9 2317 2423 1802 2504 2642 1790 Example 10 2521 3063 1002 2711 2991 912 Example 11 1883 2346 980 1790 2491 1000 Example 12 1317 1523 802 1404 1602 900 Table 3 gives the normalized values of the maximum luminosity of each sample in the examples of Table 2 . table 3

 Time

 3. 33 6. 66 9. 99 13. 32 16. 65 19. 98 ms milliseconds milliseconds milliseconds milliseconds normalized brightness ^

 Reference sample 1 0.63445 0.97087 0 0.60308 1 0

 Reference 2 0.73903 1 0.71594 0.90531 0.97691 0.70554 Example 1 0.896 0.97857 0.53286 0.93914 1 0.596 Example 2 0.97833 1 0.50155 0.9226 0.96687 0.45913 Example 3 0.9324 0.99163 0.66934 0.98226 1 0.65663 Example 4 0.96207 1 0.46621 0.93897 0.98103 0.44586 Example 5 0.96901 1 0.70428 0.93499 0.98148 0.65072 Example 6 0.9037 0.94847 0.71144 0.9634 1 0.67946 Example Ί 0.67453 0.93228 0.70249 0.6457 1 0.65924 Example 8 0.80108 0.97415 0.72977 0.78774 1 0.75104 Example 9 0.87699 0.91711 0.68206 0.94777 1 0.67752 Example 10 0.82305 1 0.32713 0.88508 0.97649 0.29775 Example 11 0.75592 0.94179 0.39342 0.71859 1 0.40145 Example 12 0.8221 0.95069 0.50062 0.8764 1 0.5618 As can be seen from Table 2 and Table 3, the luminescence of the present invention in the alternating current cycle is relatively stable, and the reference sample 1 is also used. The conventional yellow YAG: Ce luminescent material LED illuminating device with a short illuminating lifetime on a commercially available blue chip package has unstable illuminance and greatly fluctuates during the alternating current period. See Table 3 for details.

 Although the illuminating brightness of the ac LED illuminating device fluctuates less during the alternating current period when the luminescent material having an excessive luminescence lifetime is used as shown in the reference 2, the energy obtained by the material in the presence of the excitation light cannot be quickly released. , causing its luminescence to be weak, which is not conducive to use as a luminescent material, as shown in Table 2. The above test examples show that the AC LED lighting device of the present invention has the advantages of small fluctuation of light emission with current variation, and has obvious novelty and creativity compared with the existing LED light-emitting device.

Claims

Claim

1. An LED lighting unit comprising an LED chip and a luminescent material capable of emitting light under excitation of the LED chip, wherein the LED chip comprises only one luminescent PN junction, and the luminescent lifetime of the luminescent material is 1 to 100 ms. The afterglow of the luminescent material compensates for the illuminating brightness in the case of non-constant current.

 The LED lighting unit according to claim 1, wherein said LED chip is driven by an alternating current having a frequency of not more than 100 Hz, preferably an alternating current of 50 to 60 Hz.

 3. The LED lighting unit of claim 2, wherein: said luminescent material has an illuminating lifetime of 10-30 ms.

 The LED lighting unit according to claim 2 or 3, wherein the luminescent material is an inorganic luminescent material, an organic luminescent material or a mixture thereof.

The LED lighting unit according to claim 4, wherein: the luminescent material is CaS _: Eu ²⁺ _; CaS : Bi ²⁺ , Tm ³ ; ZnS: Tb ³⁺ ; CaSrS ₂ : Eu ²⁺ , Dy ³⁺ ; SrGa ₂ S ₄ :Dy ³⁺ ; Ga ₂ 0 ₃ :Eu ³⁺ ; (Y,Gd)B0 ₃ :Eu ³⁺ ; Zn ₂ Si0 ₄ :Mn ²⁺ _; YB0 ₃ :Tb ³⁺ ; Y(V,P)0 ₄ :Eu ³⁺ ; SrAl ₂ 0 ₄ :Eu ²⁺ ; SrAl ₂ 0 ₄ :Eu ²⁺ , B ³⁺ ;

SrAl ₂ 0 ₄ :Eu ²⁺ , Dy ³⁺ , B ³⁺ _; BaAl ₂ 0 ₄ :Eu ²⁺ ; CaAI ₂ 0 ₄ :Eu ²⁺ ; Sr ₄ Al ₁₄ 0 ₂₅ :Eu ²⁺ ;

Sr ₄ Al ₁₄ 0 ₂₅ : Eu ²⁺ , Dy ³⁺ , B ³⁺ ; Sr ₃ Si0 ₅ : Eu ²⁺ , Dy ³⁺ ; BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , Mn ²⁺ ;

b(acac) ₂ (AA)phen _; Y ₂ 0 ₂ S:Eu ³⁺ ; Y ₂ Si0 ₅ :Tb ³⁺ ; SrGa ₂ S ₄ :Ce ³⁺ ; Y ₃ (Al,Ga) ₅ 0 ₁₂ :Tb ³⁺ ;

Ca ₂ Zn ₄ Ti ₁₅ 0 ₃ 6 :Pr ³⁺ ; CaTi0 ₃ :Pr ³⁺ _; Zn ₂ P ₂ 0 ₇ :Tm ³⁺ ; Ca ₂ P ₂ 0 ₇ :Eu ²⁺ , Y ³⁺ ; Sr ₂ P ₂ 0 ₇ : Eu ²⁺ , Y ³⁺ ;

Lu ₂ 0 ₃ : Tb ³⁺ _; Sr ₂ AI ₆ 0": Eu ²⁺ ; Mg ₂ Sn0 _4: Mn ²⁺ ; CaAI ₂ 0 ₄ : Ce ³⁺ , Tb ³⁺ _; Sr4AI ₁₄ 025 : Tb ³⁺ ; Caio(P0 ₄ )6(F,Cl) ₂ : Sb ³⁺ , Mn ²⁺ ; Sr ₂ MgSi ₂ 0 ₇ :Eu ²⁺ ; Sr ₂ CaSi ₂ 0 ₇ :Eu ²⁺ ; Zn ₃ (P04) ₂ : Mn ²⁺ , Ga ³⁺ ;

CaO:Eu ³⁺ _; Y ₂ 0 ₂ S:Mg ²⁺ , Ti ³⁺ _; Y ₂ 0 ₂ S:Sm ³⁺ ; SrMg ₂ (P0 ₄ ) ₂ : Eu ²⁺ , Gd ³⁺ ;

BaMg ₂ (P0 ₄ ) ₂ : Eu ²⁺ , Gd ³⁺ ; Zn ₂ Si0 ₄ : Mn ²⁺ , As ⁵⁺ ; KLaF4 : Er ³⁺ ; CdSi0 ₃ : Dy ³⁺ ;

One or more of MgSi0 ₃ : Eu ²⁺ , Mn ²⁺ is mixed.

 The LED lighting unit according to claim 2 or 3, wherein the light emitted by the LED chip is ultraviolet, visible or infrared light.

 An AC light-emitting device, comprising: an AC driving circuit and at least one LED lighting unit according to any one of claims 1-5;

 Wherein, the AC drive circuit is a unidirectional series circuit, an inverse parallel circuit, a bridge rectifier circuit, or any combination thereof.

8. The alternating current LED lighting device of claim 7, wherein: the LED lighting device further comprises Light guide overlay.

 The AC LED lighting device according to claim 8, wherein: said light guiding coating layer is doped with particles of non-luminescent material having a particle diameter of less than 5 μm.

 10. The use of a light emitting unit comprising an LED chip and a luminescent material capable of emitting light under excitation of the LED chip, wherein the luminescent lifetime of the luminescent material is 1 to 100 ms, and the LED chip is only included An LED chip that emits a PN junction.